The objectives of this application are: 1) to define autoimmune disease related human T-cell receptor (TCR) V-beta alleles; and 2) to study the mechanisms of transcriptional regulation of the V-beta genes, which may provide guidance for future gene therapy for autoimmune diseases. Preliminary research results from several groups have reported that TCR V-beta-12, V-beta-17 genes are over-expressed by the T-cells in synovial tissue of rheumatoid arthritis (RA) patients or in the CSF of multiple sclerosis (MS) patients. It has been proposed that these V- beta genes may be involved in the pathogenesis of the autoimmune diseases. The investigators have, therefore, chosen to concentrate on those V-beta genes. Specifically, they will determine: a) the extent of allelic polymorphism of particular V-beta genes; b) whether any single allele of a particular V-beta gene is predominately used in a disease situation; and c) how expression of such genes (or alleles) is controlled. (I) AUTOIMMUNE DISEASES RELATED TCR V-BETA ALLELES. They will characterize the genomic structure of selected V-beta genes. Specific V-beta probes will be derived from the genomic clones and used to define restriction fragment length polymorphisms (RFLPs) and allelic variations. The sensitive method of SSCP (single strand conformational polymorphism) will be used to screen disease related V-beta alleles in patients with autoimmune diseases. (II) TRANSCRIPTIONAL REGULATION OF TCR V-BETA GENES. The promoter sequence for selected V-beta genes will be obtained and subjected to further analysis to identify the regulatory elements and motifs. The promoter activities between different V-beta genes will be compared by in vitro transcription assays (luciferase assay). The effects of several unique motifs found in the promoter of V-genes, such as the decamer sequences, Alu repetitive elements, GT-boxes, and (GT)n repeats, will also be examined. They will also determine the specific DNA binding proteins important for transcription.Results from these experiments are expected to provide guidance for future gene therapy.